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@uiten tstre' stent @titre Letters Patent No. 79,980, dated July 14, 1868'. l

IMPROVEMENT IN MACHINES FOR GRINDING SAWS.

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'.IQALL WI-IOM IT MAY OONGERN;

Beit known that I, CHARLES W. Hummm), of Pittsburg, in the county of Allegheny, and State of Pennsylvania, haveinvented a new and useful Improvement in Machines for Grinding Saws; and I do hereby declare` that the following isa full and exact description thereof, reference'being had to the accompanying drawings, and to the letters and figures of reference marked thereon. i

Y The nature of my invention consists in providing machines for grinding saws with a metallic belt, which, in

connection with feed-rollers, will move the sow-blade up to the action of the grindstone with a force only equal to the grinding-capacity ofthe grindstone.

My invention also consists in pivoting the 'nearing-roller of said machine, so that said roller and that part of the metallic belt which travels over it can b e deliected withrelation to the grinding-surface of the grindstone equal tothe bevel desired in the saw'blade. 4

i My invention also consists in providing the axis of grindstones with a iienge `which .canb'e 'adjusted to any inclination of the sides of the grindstonc's. i

To enable others skilled in the art to make and use my invention, l will proceed to describe its construc- 'tion and operation. i

vIn the accompanying drawings, which form part of my'specilcation- Figure'l is a side elevation of my improvement in machines for grinding saws.

Figure 2 is an end 'elevation ofthe same.

Figure 3 represents :1. transverse section of the frame of the grinding-machine, eut through at line y', with all the different parts of the machinery removed, except the hlearingn-oller A and its bearings and operatinggear. Y i

Figure 4 represents a transverse section of the grindstone and a longitudinal section of its shaft; also shows the soclcet-iiange and its clampingenut. Y 4

In tho drawings,` A represents the frame of the machine. p Upon this frame are placed east-iron pedestals, marked B', in'which are made the beatings for the shaft 16 of the drum D, and on which rest the bearings J for the shaft 18 lof the drum B, also the bearings'l ofthe feed-rollers 1 and 2, and to-which are` secured the columns D', upon which more the bearings X for the shaft O of the grindstone'C. The shaft O is held in its bearings by means of caps 20 and set-screws n. The hearings X are'moved upand down on the column D by means of screws f, which are madcoperativc through the medium of the Wheels 7, 8, 9, and .6. On the shafts O and 1G are plnccd pulleys P and P, around which is placed a cross-belt, It. The roller A! has its bearings at lS in the arms'17 of the piecel marked'g, which is pivoted at 14 to the armvmarlied u,'whicl1`is attached to the end of the lover w, which is pivoted in the piece mhrked 12. The lever wis held in the desired position by mcans ofthe notches 1, 2, and 3 in the piece marked X. The piece g is provided with trunnions 13, which have their bearings in the' supports marked V,

The metallic belt or endless apron marked passes between the fecd-rollers 1 and 2, and over thc upper side ofthe'bearing-rollcr A', and around the drums B and D. The tension of the metallic belt or endless apron e is regulated hy-means of the set-screw, K, through the medium of which the bearings J ofthe axle 1S of the drum Bruay be moved back or forward, and 'thereby obtain the desired distension of the metallic belt or apron e. The sides of the grindstone C are very .often inclined, or thicker at one side than at the other, (when viewed in cross-seotion,) as clenrly indicated by the liney in fig. 4. To overcome this diiiculty the opening in the flange t', through which thc'axle O passes, is made grcuter than the diameter of the axle, and in the outer face of the ilange is made a coneavity into which is fitted the inner end of the screw-nut Z,V By this arrangement of the flange and screw-nut Zielearlyshown in fig. 4) the grindstone can he secured firmly on the shaft O, without subjecting the shaft to undue strain, which is always the case when the sides of the grindstonc are inclined und the flanges are forced up against the side of the grindstonc in thc ordinary manner.

As the construction and arrangement of the several parts of my improvement in machines for grinding saws Will bercedily seen and understood hy thc skilful mechanic by reference to the accompanying drawings,

. lasso I will'thereforc, without further descriptionof/its construction, proceed to describe its operation, which is as follows: i .l y

yAll things being arranged as herein described and represented, motion is imparted to the pulley P', which will revolve the grindstone C. From the pulley P to pulley P, motion istransmitted through the medium of the cross-belt R, which motion should be so arranged witlrrelatio'n to'v other pulleys or gear as toimpart tothe drums B and D, feedrollers l'and 2, and vbeariIig-roller A and metallic belt or 'endless apron e, an alternate or reciprocating motion. mediumv of the set-screws m, ythe saw-blade to be ground is placed upon the metallic belt e, vwhich will carry it under the feed-roller I, and the combined action of the metallic belt and feed-rollers 1 and2 will carry'the saw back'and forward under the 4grindstone C, which is brought in contact with the saw-blade by -turning the wheel h, which will turn wheels 6 and 8, which will turn wheels 7 and 9,1which will turn the screwsf, which will 'lower the bearings X of the shaft O, and thereby bringl the grndstone C in contact with the saw-blade.- The bearingroller A will hold up the metallic belt e, and thereby keep the saw-blade in contact withthe grindstone. The desiredbevely is given to the saw-bladev by deilecting the bearing-roller A from its horizontal plane, as indicated by the dotted lines marked 10, (see fig. 3.) This deflection o t the roller A is accomplished by moving the lower end of the piece g, as indicated by the dotted lines marked 11,' which is done through the medium of the arm u and lever w, which can'bo held in the desired position by means ofthe notches 1 2, and 3, in the piece X.

The advantage of feeding the saw-blade upto the action of the grindstone through thel medium of the metallic belt, combined with the action ofthe feed-rollers 1 and 2, is'that the belt will only feed the saw upto the griudstone in proportion to its grinding-power; that is to say, the belt will slip or yield back on the drums B and D, so that the saw will not be carried under the grindstonefaster than it is-cut or ground off on a given plane. By thus feeding the saw up' to the grindstone with that speed and force which are justequal to its grindi'ng-capa'eity7 the result will -be the production of a saw-blade having a smooth and,even surface;-a resultwhich cannot be obtained with a feed-device, the action of which is positive and unyielding. I

The advantage of dedecting the bearing-roller A from its horizontal plane is, that through the medium of such deflection, any desired bevel of the saw-blade may beobtained, which bevel will in every case be uniform,

the advantage of which will be apparent to every mechanic skilled in the art of grinding or using saws. Y

Having-thus described the nature, construction, and operatioriofA my improvement, what I claim-asiel' my invention, is-

A1. Providing a sawgrinding machine with an unjointed thin metallic belt or endless apron, substantiallysas herein described and for` the purpose set forth. l K

. 2. Pivoting the bearing-roller A so that it can be deflected to correspondto the desired taper lof the sawblade, substantially as herein described and for the purpose set forth.`

3. Providing the shaft of a grindstone with a flange provided with a socketLjoint, `substantially as herein described and for the purpose set forth. i

C. W. HUBBARD.

Witnesses:

JAMES J. JOHNSTON,

A. C. JoirNsroN.

The tension of the feed-rollcrs 1 and 2 upon the metallic belt e being adjusted through the 

